1. Technical Field
The present invention relates to a method of manufacturing an electrophoretic display device, an electrophoretic display device and an electronic device, and more specially relates to a method of manufacturing an electrophoretic display device, the electrophoretic display device manufactured by the method, and an electronic device provided with the electrophoretic display device.
2. Related Art
It is generally known that, if electric fields are allowed to act on a dispersion system in which fine particles are dispersed in liquid, the fine particles move (or migrate) in the liquid by the Coulomb force. This phenomenon is referred to as electrophoresis. In recent years, an electrophoretic display device that displays desired information (images) using the electrophoresis draws attention as a new display device.
The electrophoretic display device is characterized by exhibiting display memory characteristics and broad viewing angle characteristics even at the time of stoppage of voltage application and by possessing a capability of performing high contrast display with reduced electricity consumption.
An electrophoretic display device is a non-luminous type (reflection type) display device. Therefore, the electrophoretic display device has such a characteristic that scarcely damage eyes as compared to a luminous type display device such as a cathode-ray tube display.
As such an electrophoretic display device, there is known a microcapsule-type electrophoretic display device that includes a pair of substrates each having an electrode, and a plurality of microcapsules arranged between the substrates and filled with a dispersion system in which electrophoretic particles (fine particles) are dispersed in a dispersion medium (JP A-2007-58151 is an example of the related art).
In the case where such an electrophoretic display device is manufactured, first, a plurality of microcapsules, a binder and liquid are mixed to each other to obtain a mixture, and then the mixture is applied onto the electrode of one substrate of the pair of substrates. Thereafter, the binder is solidified by removing the liquid contained in the applied mixture, thereby the plurality of microcapsules contained in the applied mixture are fixed on the electrode of the one substrate.
However, in this method of manufacturing the electrophoretic display device, a viscosity of the mixture to be supplied onto the electrode of the one substrate becomes high. Therefore, in the case where the mixture in which the plurality of microcapsules and the binder are mixed to each other is supplied onto the electrode of the one substrate, there is a case that the plurality of microcapsules overlap with or ride on each other in a thickness direction of the substrate.
If the plurality of microcapsules overlap with or ride on each other as described above, intensity of electric fields which are allowed to act on the electrophoretic particles included in the plurality of microcapsules becomes ununiform. As a result, it is known that the electrophoretic particles are moved ununiformly so that variations in display occur and contrast is lowered.
Further, when the plurality of microcapsules and the binder are mixed to each other to obtain the mixture, there is a fear that bubbles are mixed in the mixture. The mixed bubbles prevent the electric fields from acting on the plurality of microcapsules. This is a growing concern that movement of the electrophoretic particles is inhibited.